Market Basket employees and supporters gathered by the thousands again Friday morning at Stadium Plaza in Tewksbury, in a huge show of support for their former chief executive, Arthur T. Demoulas.The Market Basket board met Friday in Boston and issued a statement that it would consider Demoulas' offer, among others, to purchase the rival family faction's 50.5 percent share of the supermarket company.Meanwhile, many of Market Basket's 71 stores in the region have empty shelves and few customers as drivers and warehouse workers, among others, continue a massive walk-off they say will continue until "Artie T." is reinstated as CEO.Check out our news partner WCVB's ongoing coverage.